2016 Tubeless CX Progress Report

Last year, we went super whole hog on the CX tubeless setup testing. We're not going to go quite as deep into it, because we already have the info from last year, we don't have to waste time with stuff that didn't work and hasn't changed, and we haven't got the time to throw at it this year, but there are some new things we did want to test so we're doing that.

New entries for rims are Easton R90SL, Kinlin XR31T, and a prototype 2017 model that may or may not make it into circulation for this cross season, plus the Range. New tires are the Schwalbe X-One, IRC, and (finally) the Clement tubeless line. We're still waiting for the IRC to arrive.

The Clement is as expected. The one gripe we can find so far is that the treads aren't exceptionally straight. The first time I rode the BOS after doing all of our inside torture testing, I immediately pulled over thinking the wheel have gone all wiggly. Of course it hadn't, it was the tire. One of the really nice things about tubeless tires as opposed to tubulars is that they are generally straighter and rounder. But yowza do they stay on tight. In the "lay a way at 45* and repeatedly push down on it" test, it holds 100% of air down to roughly 21psi on all rims. On the Easton, it even does a little better than that. For what it's worth, many tubular glue jobs would probably come unstuck in this test. In use, no burps. And while there is no LAS tread in tubeless as yet, the other Clement treads that you know and love are present and accounted for.

The Schwalbe is also really solid, similar to the Clements. Not entirely sure of the X-One tread. It's sort of kind of a similar-ish tread to like the Kenda Small Block 8? It's knobbier than a file tread, but the knobs are super close together. It would pack up instantly in mud (it's been dry AS A BONE around here lately) and in dry conditions I think the Hutchinson Black Mamba is the fastest tire alive. I have a man crush on that tire something bad.

For rims, the Kinlin is actually surprising us with how it does. Every tire thus far has inflated on it with just a floor pump and not really even very vigorous pumping. It doesn't stay as ultra secure down into the low low inflations that many of the other combos do, but a couple of extra psi and it's secure like what.

The prototype rims have been quite good, which hasn't been surprising. We knew they would be. They're hush hush so we can't open the kimono on those.

At this point, none of the combos we've tested have shown anything like a catastrophic burp. In the most extreme cases, some have gotten a little more squishy, but the "holy crap there's no air in the tire anymore!" moment doesn't happen.

Since I have to say it absolutely every time I talk about tubeless, yes we know that no tubeless setup will ever match the absolute performance of FMB or Dugast tubulars at 16 psi. But at the 23 to 26 range where tubeless works best, the setups that we've worked with are as secure as glue.

What is the weight on the clements. I've herd they are quite heavy compare to the non-tubeless version.

Salvatore on July 25, 2017

Curious how you find the IRC tires? I've been using their RBCC road tubeless and think it is a better option than the Schwalbe Pro One. Better ride feel, grip, and durability. I also tried their Formula Light, and while it was a nice riding tire, not as durable or grippy as the RBCC.

Dave on July 25, 2017

Hi AC, sorry we haven't. When velocity brought extruding back to US, it really disrupted their quality. I can say 100% that every velocity-based wheel we put out was a much-better-than-good wheel, but it took an unholy pile of rejects to get there. And while there's nothing – literally nothing – that we like better than to have long and productive and valuable relationships with suppliers (looking at you, White Industries) we've just moved on. That said I bet they work pretty well. The tubeless bed is a good design (I think Kirk Pacenti actually designed it)

AC on July 25, 2017

I may have missed it, but have you ever tested tubeless CX on Velocity A23 rims? They are allegedly tubeless ready. Despite having two sets of November wheels, my ratty old canti brake CX was converted to SS with non november built A23s.

Dave on July 25, 2017

Hi Eric,Of course they are heavier than the non-tubeless. They need a stronger sidewall and the bead area gets reinforced. This is balanced by the removal of the tube from the system weight. The weight of a non-tubeless tire without a tube is a non-issue because the non-tubeless versions don't work tubeless to any reliable level. The tire weights are in the mid to high 300s of grams which is in line with other tubeless CX tires.

We thought it would be nice to get a bit granular on why we've specifically selected some of the carbon rims we're building with now, so here is what we like about the Knight 29 Race rim and what uses to which it's best suited.